9. The switch in the circuit of Fig. 8.55 has been closed a ridiculously long time

before suddenly being thrown open at t = 0. (a) Obtain expressions for i, and v

in the circuit of Fig. 8.55 which are valid for all ≥ 0. (b) Calculate i(t) and

310

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CHAPTER 8 BASIC RL AND RC CIRCUITS

v(1) at the instant just prior to the switch opening, at the instant just

switch opening, and at t = 470 µs.

10 Ω

25 2

10 V

FIGURE 8.55

7+1=0

50 Ω

40 mH